Fixing device

ABSTRACT

The invention relates to a fixing device ( 1 ) for fixing at least one support arm ( 45 ), in particular a spring arm. Said device comprises a base body ( 2 ), which has a connecting section ( 4 ) located in the axial direction ( 28 ) at the upper end of the base body ( 2 ) for suspending the fixing device ( 1 ) and at least one bearing section ( 5 ), which is at least partially cylindrical, whereby a bearing sleeve ( 44 ) of the support arm ( 45 ) can be mounted onto said bearing section ( 5 ). The latter ( 5 ) lies in the axial direction ( 28 ) at the lower end of the base body ( 2 ) and projects axially beyond the rest of said base body ( 2 ). In addition, a retaining ring ( 46 ) can be fixed to the bearing section ( 5 ) for retaining the bearing sleeve ( 44 ) of the support arm ( 45 ) on the bearing section ( 5 ). The bearing sleeve ( 44 ) is at least indirectly supported on the retaining ring ( 46 ) and can be rotated about the axis ( 3 ) of the bearing section ( 5 ).

[0001] The invention relates to a fixing device for fixing at least onesupport arm, in particular a spring arm.

[0002] For the purpose of supporting medical apparatus, in hospitals,doctors' practices and similar establishments supports are used whichare suspended on the ceiling of the particular treatment room oroperating theatre by way of a support arm which is preferablyconstructed as a spring arm. This ensures that the floor of thetreatment room or operating theatre is always freely accessible and, inparticular, easy to clean and to disinfect, so that the specifiedhygiene requirements can be fulfilled. In order to suspend the supportarm on the ceiling of the particular treatment room or operatingtheatre, a fixing device is required, which, where possible, enables thesupport arm to be pivoted horizontally so that, if necessary, inconjunction with the adjustment possibilities afforded by the supportarm, it is possible to effect a relative change in the orientation andposition of the medical apparatus in the treatment room or operatingtheatre.

[0003] A fixing device of this type is provided for example by thefixing device disclosed in DE 298 18 108 U1, which has the genericfeatures of claim 1. The known fixing device has a base body, which maybe fixed to the ceiling by a connecting element, for example by means ofscrewed inserts, arranged on a connecting portion of the base body.Provided alongside the base body, there are two mutually opposingbearing journals which are open towards the top, i.e. in the directionof the ceiling, and which are connected towards the bottom, i.e. in thedirection of gravity, to bearing plates. It is possible to push abearing sleeve of a support arm onto each bearing journal, the bearingsleeve being supported against gravity by the bearing plates. Part ofthe base body of the fixing device is arranged between the two bearingjournals.

[0004] The fixing device known from DE 298 18 108 U1 has severaldisadvantages. Since the bearing journals are arranged alongside thebase body, the rotatability of a support arm fixed on the bearingjournal by means of its bearing sleeve is substantially restricted,since the support arm strikes the base body of the fixing device after acertain degree of rotation. Moreover, the rotatability of the supportarm is further impaired since the two bearing journals lie opposite oneanother and thus the rotation of the support arm is impaired by thesupport arm fixed on the other bearing journal.

[0005] A further disadvantage of the known fixing device is that, as aresult of the fact that the bearing journal is arranged alongside thebase body, the bearing-journal axis, which defines the axis of rotationof the support arm, is spaced from the centre axis of the base body,producing a lever arm as a result of the spacing. Consequently, theweight-induced force of the spring arm and the apparatus fixed thereto,which acts on the bearing journal, generates a torque acting on thefixing device, so that, in addition to the weight-induced load, anadditional torque-induced load has to be taken up by the fixing deviceand the connection between the fixing device and the said ceiling.

[0006] Moreover, in the case of the known fixing device, in the event ofan—in particular jolt-like—raising of the support arm for the purpose ofchanging for example the vertical position of an apparatus, there is arisk of the bearing sleeve of the support arm springing out of thebearing journal, which can result in considerable human injury anddamage to equipment.

[0007] Therefore, the object of the invention is to provide a fixingdevice which enables a support arm fixed thereto to rotate in a desiredmanner, in particular any manner, whilst preventing an unnecessary loadon the fixing device and taking into account the stringent safetyrequirements.

[0008] The object is achieved by a subject-matter having the features ofclaim 1. Advantageous further developments of the invention are possibleas a result of the measures described in the subclaims.

[0009] The fixing device according to the invention has the advantagethat the support arm fixed to the bearing portion of the base body bymeans of the bearing sleeve is capable of rotating in any manner, sincethe bearing portion is arranged in the axial direction at the lower endof the base body and projects axially beyond the remaining base body, sothat the fixed spring arm is not impeded by the base body duringpivoting. Moreover, the bearing sleeve of the support arm is held on thebearing portion by means of a retaining ring which may be fixed to thebearing portion, so that the bearing sleeve of the support arm issecured by the retaining ring and can only be removed once the retainingring is released from the fixing device. The bearing portion isfurthermore arranged in the axial direction at the lower end of the basebody, so that a weight-induced force acting on the bearing sleeve fixedto the bearing portion produces at least substantially no additionaltorque which acts on the fixing device.

[0010] In advantageous manner, a first bearing element is provided whichat least partially surrounds the bearing portion of the base body and atleast partially abuts against the retaining ring, the bearing sleevebeing supported on the retaining ring by means of the first bearingelement. The first bearing element and the retaining ring form a firstbearing in which the bearing sleeve of the support arm is supported.

[0011] Here, support is provided at least in the axial direction of thebase body, i.e. in the direction of gravity, in order to ensure therotatability of the support arm even under a heavy load, produced forexample when a heavy apparatus is fixed to the support arm. It ispossible for the first bearing formed by the first bearing element toalso provide radial support, particularly when high torque-inducedforces acting on the bearing sleeve are expected.

[0012] It is furthermore advantageous that a second bearing element isprovided, which at least partially surrounds the bearing portion of thebase body and forms a second bearing for supporting the bearing sleeve,said second bearing lying opposite the first bearing formed by the firstbearing element. Thus, the bearing sleeve is supported on both sides,ensuring particularly good rotatability of the support arms.

[0013] In advantageous manner, the second bearing element of the secondbearing is constructed in the form of a sleeve, radial support beingprovided by the second bearing. It is furthermore advantageous that thefirst bearing element of the first bearing is constructed in the form ofa circular ring, axial support being provided by the first bearing.Since, owing to the geometrical arrangement, the weight-induced force ofthe support arm acts substantially on the first bearing, whilst anytorque produced acts almost exclusively on the second bearing, thespring arm is thus supported in a manner which is adapted to the load.For the purpose of taking up any torque produced, it is neverthelessadvantageous that the second bearing also provides axial support and/orthe first bearing also provides radial support.

[0014] In advantageous manner, the retaining ring may be fixed to thebearing portion of the base body by at least one retaining screw. Here,the retaining screw can engage in a threaded bore constructed in thebearing portion of the base body, or in a groove constructed in thebearing portion of the base body. The retaining screw can neverthelessbe applied against the surface of the bearing portion of the base bodywith an arresting force for the purpose of generating a static frictionforce for fixing the retaining ring. In any case, the retaining screwprovides numerous fixing possibilities, which can be realised inconstructively simple manner.

[0015] It is advantageous that the external diameter of the retainingring corresponds at least approximately to the external diameter of thebearing sleeve of the support arm to be fixed. Thus, the reliability ofthe retention of the bearing sleeve of the support arm is improved bymeans of the retaining ring fixed to the bearing portion of the basebody, since, for geometrical reasons, mechanical influence, for exampledue to a cable hanging down, is prevented from affecting the retainingring.

[0016] It is advantageous that the base body is constructed at leastsubstantially in the form of a tube, since this enables a compactconstruction of the fixing device to be achieved.

[0017] It is advantageous that the fixing device has a securing meanswhich may be fixed to the connecting portion of the base body for thepurpose of securing a connection which is formed by the connectingportion for the purpose of suspending the fixing device. Here, thefixing device can be fixed to the ceiling of the treatment room oroperating theatre for example by means of a connecting portion. If theconnection becomes loose, for example as a result of an excess load oran accident, then the securing means supports the drop of the fixingdevice and thus at least partially the suspension of the support arm.

[0018] In advantageous manner, a plurality of bearing portions areprovided for fixing a plurality of support arms, which are arrangedsuccessively in the axial direction of the base body, each of thebearing sleeves of the support arms abutting against at least oneretaining ring for the purpose of support. It is thus possible for aplurality of support arms to be fixed to the fixing device in rotatablysupported manner. As a result of the successive arrangement of therespective bearing portions in the axial direction of the base body,each of the support arms is able to rotate fully, without therotatability of one support arm being influenced by the other supportarms.

[0019] It is advantageous that the fixing device has a bearing journalarranged alongside the base body, it being possible to push a bearingsleeve of a support arm onto said bearing journal. It is thus possibleto use the space available alongside the base body to fix a support armfor which total rotatability is not required.

[0020] Exemplary embodiments of the invention are illustrated insimplified manner in the drawing and explained in more detail in thedescription below. There is shown:

[0021]FIG. 1 a fixing device according to a first exemplary embodimentof the invention;

[0022]FIG. 2 that detail of the fixing device which is denoted by II′ inFIG. 1 according to the first exemplary embodiment, in an axialsectional illustration along the section line denoted by II;

[0023]FIG. 3 a section through the fixing device according to the firstexemplary embodiment along the section line denoted by III in FIG. 1;and

[0024]FIG. 4 that detail denoted by II′ in Fig.1 according to a secondexemplary embodiment of the invention.

[0025]FIG. 1 shows a first exemplary embodiment of a fixing device 1according to the invention. The fixing device 1 serves for fixing asupport arm, in particular a spring arm, to a ceiling of a treatmentroom of a medical establishment or the like. By means of the support armfixed to the ceiling by the fixing device, it is possible to suspend inparticular screen viewing instruments and other medical instruments suchthat they are clear of the floor. However, the fixing device 1 is alsosuitable for other applications.

[0026] The fixing device 1 comprises a base body 2 having a connectingportion 4, which, with respect to the axis 3 of the base body 2, isarranged in the axial direction at the upper end of the base body 2, anda bearing portion 5, which is arranged in the axial direction at thelower end of the base body 2. The connecting portion 4 is connected to atubular intermediate portion 8 of the base body 2 by means of screwconnections 6, 7. The bearing portion 5 is constructed on a bearing body9, which is screwed to the intermediate portion 8 by means of the screwconnections 10, 11. In order to reduce the weight of the bearing body 9,this latter has an axial through bore 12. When the fixing device 1 isfixed to a rail attached to the ceiling by means of a moving carriage,the through bore 12 moreover serves as a through bore for the brake-rodunit of the moving carriage.

[0027] The connecting portion 4 of the base body 2 has a connectingplate 13 and a connecting body 14, which is connected to the connectingplate 13 and into which the screws 15, 16 of the screw connections 6, 7are screwed. Provided along the periphery of the connecting plate 13,there are a plurality of connecting points, in particular threeconnecting points, of which the connecting point 17 is illustrated inFIG. 1. According to the first exemplary embodiment, screw elements 18are arranged on the connecting point 17 and enable the fixing device 1on the connecting plate 13 to be connected to the ceiling of a treatmentroom or the like.

[0028] The connecting body moreover has a securing eye 19, which isconnected to a securing chain 20. Here, the securing chain 20 in theexemplary embodiment described comprises two chain elements. Thesecuring chain 20 connects the securing eye 19 to a securing karabiner21, which is constructed as a snap karabiner. The securing karabiner 21may be suspended in a securing element 22, which is of an angularconstruction in the exemplary embodiment described. The securing element22 and the connecting plate 13 can be fixed to the same ceiling. Theconnecting plate 13 and the securing element 22 can also be fixed todifferent ceilings, particularly when the connecting plate 13 is fixedto an intermediate ceiling. The securing eye 19, the securing chain 20,the securing karabiner 21 and the securing element 22 form a securingmeans 23 of the fixing device 1, which secures a connection which isformed by the connecting plate 13 of the connecting portion 4 for thepurpose of suspending the fixing device 1. So that all the components ofthe fixing device 1 are secured, the securing eye 19 is fixed to thebearing element 9.

[0029] The bearing body 9 is connected to a bearing journal 26 by meansof the connecting plates 24, 25, the connections being produced forexample by welding or hard soldering. The bearing journal 26 has acylindrical bearing portion 27, which is open towards the top, i.e. inopposition to the axial direction 28 along the axis 3 of the base body 2of the fixing device 1. When the fixing device is assembled, the axialdirection 28 of the base body 2 is preferably orientated at leastsubstantially in the direction of gravity, i.e. the axial direction 28points downwards. A bearing sleeve 30 of a support arm 31 may be pushedonto the bearing portion 27 in order to fix the support arm 31 to thefixing device 1. Here, the weight-induced force of the support arm 31,and the weight-induced forces acting on the support arm 31, hold thebearing sleeve 30 of the support arm 31 against gravity, i.e. in thedirection 28, on the bearing portion 27 of the bearing journal 26 of thefixing device 1. It is advantageous here that the bearing portion 27 ofthe bearing journal 26 projects at its upper end 32 beyond the upperedge 33 of the bearing sleeve 30, which is pushed completely onto thebearing portion 27, in order to achieve advantageous support and toprevent the bearing sleeve 30 being released from the bearing portion 27of the bearing journal 26 in the event of the support arm 31 beingraised with respect to the fixing device 1. In order to secure thebearing sleeve 30, it is possible to provide a spring lock washer whichis arranged at the upper end 32 of the bearing journal 26.Alternatively, a securing spring, which prevents the bearing sleeve 30from being raised, can be arranged at the upper end 32 of the bearingjournal 26.

[0030] The first exemplary embodiment of the invention is described inmore detail below, with additional reference to FIG. 2. Here,corresponding elements are provided with the same reference numerals inFIG. 2 and in all of the other Figures, which means that it is possibleto avoid repetitious description.

[0031]FIG. 2 shows that detail of the fixing device 1 which ischaracterised by II′ in FIG. 1 in an axial sectional illustration alongthe section line denoted by II.

[0032] The bearing body 9 has an intermediate shoulder 40, at which thebearing portion 5 merges into the connecting part 41 of the bearing body9, on which the screws 42, 43 of the screw connections 10, 11 engage inthe bearing body 9 and the connecting plates 24, 25 are fixed. Thebearing portion 5 has a constant cross-section in the axial direction 28and is open towards the bottom, i.e. in the axial direction 28. Abearing sleeve 44 of a support arm 45 is mounted on the bearing portion5. A retaining ring 46 is moreover mounted on the bearing portion 5, itbeing possible to connect said retaining ring to the bearing portion 5for the purpose of holding the bearing sleeve 44 of the support arm 45on the bearing portion 5.

[0033] In the exemplary embodiment described, the connection is effectedby way of three screw connections, which are described in more detailbelow with reference to FIG. 3. Here, FIG. 3 shows a section through thefixing device 1 according to the first exemplary embodiment along thesection line denoted by III in FIG. 1.

[0034] The retaining ring 46 has threaded bores 50, 51, 52 which arearranged opposite the bores 53, 54, 55 in the bearing portion 5 of thebearing body 9. Screw elements are screwed into the threaded bores 50,51, 52 of the retaining ring 46 for the purpose of fixing the retainingring 46 on the bearing portion 5 of the bearing body 9, said screwelements having a pin-shaped portion at their end, which engages in thebores 53, 54, 55 in the bearing portion 5. This secures the retainingring 46 against torsion and also against axial displacement with respectto the axis 3 of the base body 2.

[0035] As illustrated in FIGS. 1 and 2, the bearing sleeve 44 issupported on the retaining ring 46 at its lower first end 60 by means ofa first bearing element 61. The first bearing element 61 is constructedin the form of a circular ring, so that the first bearing 62 formed bythe first bearing element 61 ensures that the bearing sleeve 44 issupported axially. The axial displacement of the bearing sleeve 44 inopposition to the axial direction 28 is delimited by the intermediateshoulder 40, the bearing sleeve 44 having a circular collar 63 which atleast partially surrounds the intermediate shoulder 40. A second bearingelement 65 is provided at the upper second end 64 of the bearing sleeve44, between the bearing sleeve 44, in particular the circular collar 63,and the bearing body 9, in particular the intermediate shoulder 40. Thesecond bearing element 65 forms a second bearing 66, which principallyensures that the bearing sleeve 44 is supported radially and, to someextent, axially. Here, the second bearing element 65 is constructedsubstantially in the form of a sleeve, whereby it at least partiallysurrounds the intermediate shoulder 40 at its lower end, i.e. on theside of the bearing portion 5.

[0036] In that exemplary embodiment of the invention described, thebearing elements 61, 65 surround the bearing body 9, and in particularthe bearing portion 5, radially, in which arrangement it is possiblyalso sufficient for at least one of the bearing elements 61, 65 tosurround the bearing body 9, and in particular the bearing portion 5,only partially or in portions in order to ensure the desired support.

[0037] Since the second bearing element 65 surrounds the bearing portion5 in the region where it has a widened diameter, i.e. at theintermediate shoulder 40, it is ensured that displacement of the secondbearing element 65 in an axial direction, in particular in the axialdirection 28, i.e. in the direction of gravity, is prevented. Since thefirst bearing element 16 is constructed in the form of a disc and isarranged between the bearing sleeve 44 and the retaining ring 46,displacement of the first bearing element 61 in an axial direction is inany case prevented.

[0038] The intermediate portion 8, the bearing body 9 and the connectingbody 14 of the fixing device are constructed at least substantially inthe form of a tube, so that the base body 2 of the fixing device 1,which is composed substantially of these components, is likewiseconstructed at least substantially in the form of a tube. Thus, with alow weight, a high degree of mechanical stability, in particulartorsion-resistance, of the fixing device 1 is achieved, as a result ofwhich the fixing device 1 withstands high torque-induced forces. In theexemplary embodiment described, the bearing body 9, the bearing sleeve44 and the retaining ring 46 have at least substantially the sameexternal diameter, thus resulting in a compact construction.

[0039] Since the bearing sleeve 44 supported in the two bearings 62, 66may be rotated through 360° about the axis 3 of the bearing portion 5 ofthe base body 2, the support arm 45 connected to the bearing sleeve 44,for example by welding, may be pivoted freely about the axis 3 in anymanner.

[0040]FIG. 4 shows that detail of the fixing device 1 which is denotedby II′ in FIG. 1 according to a second exemplary embodiment.

[0041] According to the second exemplary embodiment, the base body 2 hasa plurality of bearing portions 5, 70, 71 on which the support arms 45,74, 75 are fixed by means of the bearing sleeves 44, 72, 73. Here, eachof the bearing sleeves 44, 72, 73 is supported on a retaining ring 46,76, 77. Here, the retaining rings 46, 76 each have a portion, 78 and 79respectively, having a smaller diameter in order to form a shoulder forthe adjoining bearing sleeve 72 or 73, which shoulder corresponds to theintermediate shoulder 40, is at least partially surrounded by a bearingelement corresponding to the second bearing element 65, and is at leastpartially encompassed by the subsequent bearing sleeve 72 or 73 at itsupper end. The last, i.e. the bottom-most, retaining ring 77 isconstructed according to the retaining ring known from the firstexemplary embodiment, since it is not adjoined by a further bearingsleeve.

[0042] Since the support arms 45, 74, 75 are arranged mutually offset inthe axial direction with respect to the axis 3, they can be pivotedindependently from one another through 360°.

[0043] The invention is not restricted to the exemplary embodimentsdescribed. According to the second exemplary embodiment, it isparticularly possible to provide any number of bearing portions in orderto fix any number of support arms to the base body 2. It is moreoverpossible for one or more bearing portions arranged mutually offset inthe axial direction, and one or more bearing journals arranged alongsidethe base body 2, to be provided on a fixing device.

1. A fixing device (1) for fixing at least one support arm (45), inparticular a spring arm, having a base body (2), which has a connectingportion (4) arranged in the axial direction (28) at the upper end of thebase body (2) for the purpose of suspending the fixing device (1), andat least one bearing portion (5) which is at least partiallycylindrical, it being possible to mount a bearing sleeve (44) of thesupport arm (45) on the bearing portion (5), characterised in that thebearing portion (5) is arranged in the axial direction (28) at the lowerend of the base body (2) and projects axially beyond the remaining basebody (2), and in that a retaining ring (46) may be fixed to the bearingportion (5) for the purpose of holding the bearing sleeve (44) of thesupport arm (45) on the bearing portion (5), the bearing sleeve (44)being at least indirectly supported on the retaining ring (46) and beingrotatable about the axis (3) of the bearing portion (5).
 2. A fixingdevice according to claim 1, characterised in that a first bearingelement (61) is provided, which at least partially surrounds the bearingportion (5) of the base body (2) and at least partially abuts againstthe retaining ring (46), the bearing sleeve (44) being supported on theretaining ring (46) by means of the first bearing element (61).
 3. Afixing device according to claim 2, characterised in that a secondbearing element (65) is provided, which at least partially surrounds thebearing portion (5) of the base body (2) and forms a second bearing (66)for supporting the bearing sleeve (44), which lies opposite the firstbearing (62) formed by the first bearing element (61).
 4. A fixingdevice according to claim 3, characterised in that the second bearingelement (65) surrounds the bearing portion (5) in a region (40) whichhas a widened diameter.
 5. A fixing device according to claim 3 or 4,characterized in that the second bearing element (65) of the secondbearing (66) is constructed in the form of a sleeve, radial supportbeing provided by the second bearing (66).
 6. A fixing device accordingto one of claims 2 to 5, characterized in that the first bearing element(61) of the first bearing (62) is constructed in the form of a circularring, axial support being provided by the first bearing (62).
 7. Afixing device according to one of claims 1 to 6, characterized in thatthe retaining ring (46) may be fixed to the bearing portion (5) of thebase body (2) by at least one retaining screw.
 8. A fixing deviceaccording to one of claims 1 to 7, characterised in that the externaldiameter of the retaining ring (46) corresponds at least approximatelyto the external diameter of the bearing sleeve (44) of the support arm(45) to be fixed.
 9. A fixing device according to one of claims 1 to 8,characterized in that the base body (2) is constructed at leastsubstantially in the form of a tube.
 10. A fixing device according toone of claims 1 to 9, characterised in that the fixing device (1) has asecuring means (23) which may be fixed to the connecting portion (4) ofthe base body (2) for the purpose of securing a connection which isformed by the connecting portion (4) for the purpose of suspending thefixing device (1).
 11. A fixing device according to one of claims 1 to10, characterised in that a plurality of bearing portions (5, 70, 71)are provided for fixing a plurality of support arms (45, 74, 75), whichare arranged successively in the axial direction (28) of the base body(2), each of the bearing sleeves (44, 72, 73) of the support arms (45,74, 75) abutting against at least one retaining ring (46, 76, 77) forthe purpose of support.
 12. A fixing device according to one of claims 1to 11, characterized in that the fixing device (1) has a bearing journal(26) arranged alongside the base body (2), it being possible to push abearing sleeve (30) of a support arm (31) onto said bearing journal(26).
 13. A fixing device according to one of claims 1 to 12,characterized in that the bearing portion (5) of the base body isconstructed in the form of a tube.
 14. A fixing device according to oneof claims 1 to 13, characterized in that the bearing sleeve (44) may berotated through 360° about the axis (3) of the bearing portion (5).